The mission of beam dynamics group
- Accelerator design and performance upgrade
- Troubleshooting and analysis of operational problems
- Development of application programs for accelerator physics
- R&D of novel accelerator-based light sources
- Accelerators for industrial/medical applications
Double mini-betay lattice in TPS
The baseline lattice of TPS storage ring consists of 24 double bend achromat (DBA) cells, 18 short straight sections (7m) and 6 long straight sections (12m). Based on the baseline lattice, three long straight sections are symmetrically configured as double mini-betay lattice in which three sets of quadrupole triplet are installed in the middles of three long straight sections respectively to accommodate two undulators as shown in Fig. 1.
The current lattice of user operation is a double mini-betay lattice with 3 superperiods, different from the baseline lattice used during the TPS commissioning. Figure 2 shows the beam optics functions for the TPS double mini-betay lattice of one superperiod.
Table 1: The accelerator parameters for the double mini-betay lattice
| Accelerator parameter |
Storage Ring |
| Energy (GeV) |
3.0 |
| Current (mA) |
400 (500) |
| Circumference (m) |
518.4 |
| Nature emittance (nm-rad) |
1.6 |
| Bending radius (m) |
8.40338 |
| Betatron tune |
26.16 / 14.24 |
| Energy loss per turn (keV) |
853 |
| Natural energy spread |
8.86 x 10-4 |
| Bunch length (mm) |
2.86 |
| Harmonic number |
864 |
| RF frequency (MHz) |
499.654 |